Self-winding watch overwind preventer



Feb. 1, 1955 FElGEL 2,700,868

SELF-WINDING WATCH OVERWIND PREVENTER Filed Aug. 25, 1953 IN VENT 0R.

Anion United States Patent SELF-WINDING WATCH OVERWIND PREVENTER AntonFeigel, Bronx, N. Y. Application August 25, 1953, Serial No. 376,409

7 Claims. (Cl. 58-83) In the construction of self-winding watches, anupper limit of the tension of the mainspring must be taken into account,and a device must be provided which prevents such limit from beingexceeded.

The most simple device for this purpose, Which is most frequently used,comprises a loose piece of thicker mainspring coiled inside the barrel.The outer end of the mainspring is riveted to said piece which engagesthe inner wall of the barrel frictionally. A disadvantage of such knowndevice is that the friction only ensures an approximate regulation oradjustment of the mainspring tension, which spring generally functionsnear its maximum tension. Furthermore, the spring is liable to getuncoiled in abrupt steps. Finally, the manufacture of 1sjuch lwatchesnecessitates the construction of a special arre.

Other known devices for regulating the tension of the mainspringcomprise a relatively large number of intermediate movable elements,which renders them expensive. Moreover, their function does not offersufficient accuracy.

Objects of my present invention are to eliminate the disadvantages ofthese known devices, to use a minimum of parts and elements, and toprovide accuracy in the function of the device for regulating themainspring tension.

Other objects and structural details of the invention will be apparentfrom the following description when read in conjunction with theaccompanying drawing forming part of this specification, wherein thesingle figure is a top plan view of the winding mechanism of aself-winding watch according to the invention.

In said figures only those parts are shown which are necessary for acomplete understanding of the invention.

In the upper face of the rockable weight 1, which is pivoted on the axle2 situated in the center of the watch movement, a recess 3 is provided.The bridge of weight 1 is partly shown at 4. On a pin 5 fixed to weight1 and situated in recess 3, is pivoted a pawl 6 of which the tip 7coacts with the teeth of the winding pinion 8 which is pivoted on axle 2of weight 1. A spring lever 9 is pivoted in recess 3 on a pin 10 fixedto weight 1. The movement of lever 9 to the right in the drawing islimited by a stop stud 11 fixed to weight 1.

A screw having an eccentric head 12 is mounted in a threaded bore ofweight 1 to coact with a face 13 of the lower portion 14 of lever 9 andpermits to regulate the latters tension.

The stud 11 is arranged on the weight 1 in such a position relative tothe pawl 6 and the finger 15 of lever 9 is of such a curved shape, thatpawl 6 just abuts against the extremity of finger 15 when it is inengagement with pinion 8 as shown in the drawing.

Spring 16 which at 17 is secured to pawl 6 by means of a pin 18, abutsagainst the wall of recess 3 at 19 and tends to move pawl 6counterclockwise.

A cover 20, only partly shown, is secured to weight 1 by two screws 21and 22 and holds pawl 6 and the springs 9 and 16 in place in recess 3.Pinion 8 is connected to the barrel arbor and ensures the winding of themainspring by gearwheels (not shown).

Let it be assumed that winding takes place when weight 1 rocks in thedirection of arrow 23. During such movement, the tip 7 of pawl 6 engagespinion 8 and moves same counterclockwise, since the spring lever 9normally prevents pawl 6 from turning counterclockwise on pin 5.

When weight 1 rocks in a direction opposite to arrow 23, while pinion 8by means not shown is held stationary with the barrel arbor, pawl 6swings clockwise on its pin 5 and its tip 7 passes simply on the crestof the teeth of pinion 8. During this movement, the leaf spring 16 urgespawl 6 in counterclockwise direction for keeping same in engagement withteeth of the pinion 8. Pawl 6 returns into its engaging position shownin the drawing, as soon as the weight 1 stops its clockwise rotation andstarts to rotate in counterclockwise direction.

After each winding oscillation, the tension of the mainspring isincreased, and the resistance which pinion 8 offers to the winding bypawl 6 increases accordingly.

Assuming now that the tension of the mainspring has attained its upperlimit which should not be exceeded for the good function of the watch.In order to eliminate any further winding, which would increase thetension of the mainspring beyond such limit, it suflices to so regulatethe force of spring lever 9 that, in its effect on pawl 6, it is lessthan the resistance of pinion 8. In such case, pawl 6 swingscounterclockwise, and its tip 7 passes on the crest of the teeth ofpinion 8 without I positively engaging the latter.

The eccentric screw 12 allows of accurately and quickly regulating thetension of spring lever 9, corresponding to the upper limit of tensionof the mainspring, thus ensuring a greater security of operation than inthe devices known so far.

While I have described and illustrated one embodiment of my invention, Ido not wish to limit the scope of this invention unnecessarily, butreserve the right to make such modifications and rearrangements of theseveral parts as may come within the purview of the accompanying claims.

I claim:

1. In a self-winding watch of the type involving a rockable weightpivoted on an axle pin situated in the center of the watch movement, theimprovement comprising a pawl pivoted to said weight, a pinion disposedcoaxially with said weight in pivotal relation and adapted to wind themainspring of the watch movement, a spring lever pivoted to said weightto engage said pawl, and a leaf spring secured to one end of said pawland abutting against said weight, the whole in such arrangement thatsaid pawl engages said pinion under the action of said spring lever andagainst the action of said leaf spring, and the spring lever permitssaid pawl to disengage itself from said pinion when the tension of saidmainspring exceeds a certain upper limit.

2. A self-Winding watch as set out in claim 1, in which the spring leverholds the pawl in its engaging position through pressure action.

3. A self-winding watch as set out in claim 1, in which the spring leveryields to the pressure of the pawl when the tension of the mainspringreaches its upper limit.

4. A self-winding watch as set out in claim 1, in which a screw havingan eccentric head and mounted in a threaded bore of the rockable weightcoacts with a face of the spring lever to permit to regulate the tensionof the spring lever.

5. A self-winding watch as set out in claim 1, in which a stop studfixed to the rockable weight limits the swing of the spring lever.

6. A self-winding watch as set out in claim 1, in which the pawl andspring lever and leaf spring are disposed in a recess in the top face ofthe rockable weight.

7. A self-winding watch as set out in claim 6, in which a cover platesecured to the rockable weight by screws covers the pawl and springlever and leaf spring and holds them in place for their respectivefunctions.

References Cited in the file of this patent UNITED STATES PATENTS1,853,637 Reiner Apr. 12, 1932 1,973,898 Henry Sept. 18, 1934 2,179,855Latimer Nov. 14, 1939

